EFFECT OF UV RAYS ON ENZYME ACTIVITIES IN RATS TREATED WITH PHYTOCHEMICALS

Abstract

Exposure of biological systems to ultraviolet A (UVA) can induce the formation of reactive oxygen species (ROS) which can cause oxidative damage to the major constituents of cells. The modifications in endogenous antioxidant capacity, including superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase, reduced glutathione (GSH) and thiobarbituric acid-reactive substance (TBARS) were measured. The ability of two diet-derived flavonoids such as the flavanone naringenin (NG) and the flavanol quercetin (QE) to modulate antioxidant enzymes activities were investigated. Male albino rats were divided into four groups (control, UV, UV+QE and UV+NG). The UV groups were irradiated every day for 4 h with UVA during periods of 15, 30, 45 and 60 days. NG or QE were administered intraperitoneally (10 mg/kg) before irradiation periods. Blood was taken 15, 30, 45 and 60 days post-treatment. The study revealed that exposure of rats to UVA leads to oxidative stress and disturbing the prooxidant / antioxidant balance of cells, reflected by increasing in malondialdehyde (MDA) and reducing in antioxidant enzyme levels. Results also indicate that NG or QE pretreatments have beneficial effects against ultraviolet-induced injury